The present invention relates to a novel and useful mechanism for cracking nuts, such as walnuts.
The processing of walnuts requires complete and careful cracking of the shells to prevent breakage of the meat into small pieces as well as the production of ground meal. In addition, shell fragments, which must be eventually removed from the cracked walnuts, should be large in size to effect such removal.
In the past, walnuts have been manually cracked by a person wielding a hammer on an assembly line, one at a time. Such cracking technique has produced good results, but is slow, extremely labor extensive, and, consequently, quite expensive to achieve. Other devices for cracking walnuts have been proposed. For example, U.S. Pat. No. 2,147,022 describes a walnut cracking device which combines a brush and rolling mechanism to crack a walnut shell on a sharp edge of a draper. U.S. Pat. No. 2,685,312 cracks walnut shells using an electric charge between both ends of the whole walnut. U.S. Pat. No. 2,288,191 cracks multiple walnuts by squeezing walnuts between a cracker head bar and a prong holder using a hydraulically driven mechanism.
U.S. Pat. Nos. 3,871,275, 4,332,827, and 4,418,617 describe apparatuses for cracking pecans which utilize an anvil that moves under air pressure against a cracking hammer to crack the pecan. The anvil is returned by a spring to its position. U.S. Pat. Nos. 4,332,827 and 4,418,617 teach conveyors which lie intermediate the source of the pecans and the turret used to crack the same.
The mechanism most often used to crack walnuts in the industry is referred as to the "dragon" machine. Generally, the "dragon" utilizes concentric rotating cones which have different slopes. Walnuts are cracked at the closest point between the two cones. Although the "dragon" possesses a high capacity, it does a relatively poor job producing quality walnut meats. That is to say, less than 15% of the meats recovered are halves. In addition, the skin is removed from the meat which is an aesthetic disadvantage. Moreover, shells, and other fragments are ground into small particles which are difficult to remove from the finished product.
A high capacity nut cracking machine that may be used to crack walnuts without damaging the meat of the walnut would be a great advance in the food processing industry.